• Ian Watts

First Road Test - Results

Updated: Aug 11, 2019

Wow ! So this is an EV grin ! I'm still picking the flies out of my teeth (yeuch) !

Wot ? No exhaust ?? !

I'm not quite sure where to start. I'm a pretty 'picky' kinda guy and normally the first to criticise my own work and the results of it so, let's start with the criticisms :

To be fair, at this stage, after 34km on Scoot-ee, I don't have many criticisms :

1: take-off is a little... 'vicious' / quick. There seems to be no gentle / soft-start I guess I'd call it. Just have to be careful when starting off that you're pointing in the right direction. To be fair, it's nothing horrible, just not quite the soft / gentle start I'd have preferred for normal kick-offs...

2: the batteries are hard to remove - I'll re-design them from long'n'thin (20 18650 cells long and 4 cells wide) to short and fat (10 cells long and 8 cells wide). The new size is just within the capabilities of Prusa mk3 printer and should allow me to fit 3 (3Kw) (in lieu of 2 - 2Kw) if I want / need to. To be fair, 34km and not dead is better than I imagined... so... 3 packs most likely will not be necessary but...

3: the V / A 'test' meter could be better. I'd like to improve upon this with a coulomb counter type meter or maybe a full screen / instrument panel to replace the one that's there... it's not a 'requirement' (especially as I scraped in, around the 800Euro budget) to be fair but, if such a display could be fitted and look good, it would definitely be better. Even better (and potentially cheaper), I suppose, would be a design that uses the fuel gauge to display remaining range. I'll try to take a look at that over the summer.

4: in an ideal world I'd have been able to keep to a belt drive. Much quieter, but really... it's a little like a turbine powering up... not loud or annoying... I'd have simply preferred EVEN quieter !

Having said that...

Top Speed

The top speed is in excess of 60kmh on the flat, down hill the rev limiter cuts in again at around 75-78Kmh but, in 'Hi' speed mode, 60kmh on the flat (wind or no wind) is readily achievable - VERY happy !


Seems more than adequate. My tests were not particularly scientific; I measured out circa 250m on a pretty flat (slightly uphill) smooth road near the house and used a stop watch from the scoot. I took the average of two runs in each direction (4 runs in total). The results :

0-30Kmh in 5.1 seconds

0-45Kmh in 9.8 seconds

0-50Kmh in 19.9 seconds

250metres from standing start 21.6 seconds

Definitely NOT blistering but better than stock. It probably didn't help that my mouth was wide open in an electric / ecstatic kind of grin - must have increased drag / resistance ;)

I'm also pretty sure that a Kelly KBL72101X controller would make a huge difference but then it would add an additional 300Euro to the budget ! But... I'd be more than happy now to swap out the controllers for a test... Currently max amps through the controller is 'limited' to 40A - it's just the controller. Loading up the two battery packs -off Scoot-ee / on the bench - through their BMS's and breakers delivers in excess of 75A so... a Kelly controller upgrade would seem to be appropriate if I need / want more dazzling performance.

Having spoken to a dozen or so 'older' 50cc scooter riders, most are 'happy' with their 45kmh (or so) top speed so I could very easily increase the rear sprocket size to increase acceleration and decrease the top end speed back down to a (more reasonable? / legal ! ) 45-50kmh... which would undoubtedly increase the range too !! Unfortunately with reduced rider age comes the need for increased top speed - or so it seems.

Motor, chain drive and swingarm cover


Impressive, almost none, just a chain 'rattle' (that's a wee bit harsh of me really, it's just the inevitable noise of a chain moving fast)... coupled with a turbo-style whine... not bad at all and a HUGE improvement over the original !! I'd still like a belt though. This motor just won't readily accept a belt very easily...

Again, if I were doing another conversion I would spend more time researching the motor and get something that could handle a belt pulley, maybe with an additional end-of-shaft bearing for less shaft stress... thoughts anyone ?

Having said all the above, I still can't quite believe it all works so well.

I'm monitoring controller temperature (fishtank-style digital thermometer clamped to two controller fins and heat paste). Currently, (just 34Kms so definitely not conclusive !), the max recorded temperature is 36'C / 97'F. Ambient temperature was 19'. I think that's OK but, again... if anyone cares to share some thoughts ?...

I'm also going to do some decent 'hill work' this week to test and check controller amps / temperature / volts...

What more can I say ?

Both batteries installed : 1KwHr each


Conversion work (give or take a wee bit) : 40 Hrs (I wasn't too fastidious with my hour count...)


Original RPS Scoot purchase price : 200 Euro

Batteries (2 x 20S4P LiFePo4 / 1Kw ea) : 498 Euro

Throttle, DCDC converter, SSRs : 75 Euro

Cable, Plugs+Sockets, Meter+Shunt : 50 Euro

Fibreglass, printer filament, paint, clips... : 25 Euro

Total (give or take a wee bit) : 850 Euro

Bear in mind,

  • I have never undertaken a conversion before...

  • I am only your standard electrician / electronics engineer...

  • Granted, I have a pretty extensive set of tools but...

  • I solder and braze regularly but, although I have a MIG welder, I have less than a full day's welding experience (slightly more now !) ...

  • I can fibre glass (used to build beach-rescue canoes etc) but there wasn't so much to do on this project. Anyways, anyone can make a cardboard template or two and apply some fibreglass, so - simple enough...


90% of this project could be undertaken without any specialist tools; a 'standard' toolbox (spanners, screwdrivers & files etc), a drill, a grinder, a multi-meter and a soldering iron.

The last 10% would involve a welder (stick would be fine, I used a MIG), a method to make up your battery pack(s) or you could buy it (them) ready made, a hot air gun and a glue gun...

Granted, I DO have use of a 3D printer and I have extensive experience with both it and Sketchup BUT neither are absolutely necessary...


Re-registration in France is all but impossible (although almost everyone and his dog "debrides" / de-restricts their scooters and 50cc motorbikes and the world seems to turn a blind eye.

Be careful though, it is illegal to ride a modified vehicle on the road here. As of mid-2019, whilst your insurance will (I believe), if you have a 'sinistre' / accident, pay out for the 3rd party damage you cause, it will, most likely, be void and NOT pay out for you or your modified ride ! You've been warned !

I'd love to see enough 50cc riders wanting to switch to electric - less noise & less pollution for 2 reasons - that we start a movement to petition our governments to allow sensible conversions - as is readily achievable in the UK.

In the UK, however, it took me less than 30 minutes to arrange (update Sections 7 (Vehicle changes & Modifications) & 8 (sign and date), in the V5 LogBook, include a valid MOT and return to the DVLA, Swansea).

The road tax then becomes zero (select Tax Class as 'Electric') and

the insurance cheaper than the original ICE scooter (I enquired of Admiral and Carole Nash).

Having said that, like I said, I live in France and haven't physically done a re-registration BUT I have spoken at length to DVLA (thanks Bob @ the DVLA) and various insurance brokers...

I have no idea as to how difficult this is in Germany, Netherlands or the US etc. but, remember there were ZERO frame, swingarm, brake or original equipment mods - all I did was remove the ICE kit and the rest is documented on my blog here on the web-site...

All of the work was completed for a total expenditure of (give or take) 1,000 Euro. That includes the original ICE scooter purchase !!! There are quite literally thousands of 50cc / 125cc scooters, mopeds and motorcycles in Europe alone that don't work but could be brought back to life for less than a thousand Euro / Pounds with almost zero running charges ! It might be illegal (strictly speaking at this time - mid 2019) to ride a conversion on the road today in France and, maybe, other countries, but in 12 months, 2 years or 5 years time and as governmental Co2 / pollution reduction targets come into force ??? Who knows ?!

To me, it seems totally mental to simply consign older, otherwise perfectly good, smaller rides to a scrapheap just because they're considered 'dirty' petrol or because they no longer want to start !

Cost Justification (No 'ECO' orange box)

Low and Ultra-Low Emission Zones are on the increase. Two to three months riding in one of these zones would pay for the conversion.


Finally, I put an OWL (energy power) meter on the charger last night. The 2 x packs were showing 67V at the start and were fully charged this morning (I think it should only take 4 to 5 hours tops from empty to full) and the meter displayed 1.4Kw of energy at 21cents (0.21 Euro) cost - for 34Kms !!!! Incredible.

Solar ?

I can't help but get all fired up over this and think I could run for free if I had roof solar - and not much of it at that !! No cost to me, reduced noise, almost zero servicing costs and no Co2 emissions damaging the planet ! What's not to like ?


I guess now, it just remains for me to :

do a lot more tests,

make a video, You-Tube it and link it here,

undertake the mods (when I've stopped grinning) and

monitor how Scoot-ee performs over the next couple of hundred kilometres (and post the results)...


Overall? Delighted, I think that says it all - I'm converted !!

I'm off for another ride !

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